Wep Security Overview - Nokia A032 User Manual

WEP security overview

Secret keys
WEP depends on the fact that both the access
point and the wireless client know a numeric
password called a key. You might enter the key
as a string (e.g. ) or as a number (e.g.
secret
) but as far as the system is
01524364732
concerned it is just a sequence of bits – both
the access point and the wireless client must
store the sequence and prove to each other that
the sequence is identical.
Key strength
The number of bits used for the key determines
the strength of the key. Generally, the more bits
there are in the key the harder it is for someone
else to crack the code. Some governments
restrict the use of very secure keys and for this
reason the IEEE802.11 standard specifies 40-bit
keys for general use. 40-bit keys provide a high
degree of security uncrackable by all but the
most determined attackers. The Nokia A032
allows the use of longer keys where local
regulations permit, up to 128 bits in length.
Such keys are essentially uncrackable by
known methods.
To put the key strength in perspective, a 40-bit
key might be cracked in about one month using
a machine capable of trying 100,000 different
keys a second. By comparison, the same
machine would take many million times the
age of the universe to crack a 128-bit key using
the same approach!
130 Nokia A032 Advanced User Guide